1. Field of the Invention
The present invention relates to a display device, and more particularly, to an liquid crystal display (LCD) device and a fabrication method thereof. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for an organic alignment layer for aligning liquid crystal molecules without rubbing.
2. Description of the Related Art
In general, an LCD device is a display device for displaying images by controlling a transmittance of light through a liquid crystal layer by using refractivity anisotropy of liquid crystal molecules. In order to obtain uniform brightness and a high contrast ratio in the LCD device, an alignment must be performed so as to align the liquid crystal molecules in a predetermined direction. Currently, an alignment method by rubbing is commonly used. According to the alignment method by rubbing, an alignment film made of a material, such as polyimide, etc., is coated on a substrate, which is then rubbed by using a rubbing roll having an alignment cloth. Thus, uniform micro-grooves are formed on the surface of the alignment film. Liquid crystal molecules are arranged in parallel to the micro-grooves on the surface of the alignment film so as to minimize elastic deformation energy.
The related art alignment method by rubbing has a problem in that if the micro-grooves formed on the surface of the alignment film are defective, phase distortion and light scattering may occur, which undesirably degrades the performance of the LCD device. In addition, rubbing causes the generation of dust and static electricity on the alignment film, which undesirably degrades a production yield and damages the substrate. Moreover, for a large-sized LCD device built on a large substrate, a large-scale heavy rubbing roll must be used for rubbing the corresponding large substrate, and in such case, it is quite difficult to perform proper rubbing on the entire surface of the substrate with the rubbing roll applying a uniform pressure.